https://devzone.nordicsemi.com/f/nordic-q-a/57423/how-to-compile-in-lower-version-of-ideHi Sir, As we know the SDK has the lowest version of IDE to compile. ========= release note of SDK 16.0 ============ The following toolchains/devices have been used for testing and verification: - ARM: MDK-ARM version 5.25 - GCC: GCC ARM Embeddeden-USTelligent Community 13Wed, 05 Feb 2020 12:09:46 GMThttps://devzone.nordicsemi.com/thread/232812?ContentTypeID=1Wed, 05 Feb 2020 12:09:46 GMT137ad170-7792-4731-bb38-c0d22fbe4515:38a20d65-570b-40bc-a170-cfca2830ef16Kenneth<p>We have not done any testing with IAR 6, if you can&#39;t update your IAR version, then I suggest to consider using Segger Embedded Studio (SES),&nbsp;because&nbsp;with SES there is a free commercial license for developing with nRF devices:</p> <p><a href="https://infocenter.nordicsemi.com/topic/ug_gsg_ses/UG/gsg/intro.html">https://infocenter.nordicsemi.com/topic/ug_gsg_ses/UG/gsg/intro.html</a></p> <p><a href="https://www.youtube.com/watch?v=YZouRE_Ol8g&amp;list=PLx_tBuQ_KSqGHmzdEL2GWEOeix-S5rgTV&amp;index=1">https://www.youtube.com/watch?v=YZouRE_Ol8g&amp;list=PLx_tBuQ_KSqGHmzdEL2GWEOeix-S5rgTV&amp;index=1</a></p> <p>Best regards,<br />Kenneth</p><div style="clear:both;"></div>